Insulating a daylight basement
Interesting-Found this on the Insulation Contractors Association of America website. Unless I'm reading it wrong, they state that putting a vapor barrier insulation below grade is not recommended.
Below-grade basement walls differ from above-grade walls in that they are vulnerable to ground
moisture wicking into the wall or basement floor. Because of this, it is important to maintain the
drying potential of the wall since one never knows if the long-term moisture drive will be from
the outside or the inside . A masonry wall is capable of absorbing large quantities of water due to
the capillary action of concrete . If the masonry wall unit has hollow cores, air movements within
the wall also increase the thermal and moisture movement . For this reason, it is recommended
that a vapor retarder not be used in a wall that is partially or fully below grade . If a wall is above
grade, such as in a walk-out basement, then that wall may use a vapor retarder, if the climate
dictates a vapor retarder in above-grade walls .
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